A low-leakage universal joint
By designing a sealed space and a balance hole connection structure in the universal joint, the problem of grease leakage was solved, achieving good lubrication and extending service life.
Patent Information
- Application Number
- CN202511477940.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2025-10-16
- Publication Date
- 2026-01-27
- Estimated Expiration
- 2045-10-16
AI Technical Summary
Universal joints are prone to grease leakage during use, leading to insufficient lubrication and affecting their service life.
A low-leakage universal joint structure was designed. By forming a sealed space between the bushing assembly and the shaft unit, and setting an annular sealing assembly in the sealed space, the inner and outer balance cavities are connected by a balance hole, which reduces the deformation of the sealing assembly, extends the movement path of the grease, and prevents grease leakage.
It effectively reduces grease leakage, ensures good lubrication of the universal joint, and extends its service life.
Smart Images
Figure CN120926198B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of universal joint technology, and more specifically, to a low-leakage universal joint. Background Technology
[0002] The universal joint is located at the end of the drive shaft and serves to connect the drive shaft to components such as the drive axle and half-shafts. A universal joint typically includes a housing, rolling elements, a shaft, and a sealing ring. The housing is fitted onto the outer circumference of the shaft, and the rolling elements are positioned between the housing and the shaft, abutting against both. The sealing ring is located between the housing and the shaft; its inner circumferential wall abuts against the outer circumferential wall of the shaft, and its outer circumferential wall abuts against the inner circumferential wall of the housing. It is positioned at the open end of the housing to prevent foreign objects from entering the enclosed space and to prevent lubricating grease from flowing from the housing into the external space of the universal joint.
[0003] During the use of the universal joint, the rolling elements roll and rub against the housing and shaft respectively. The friction generates heat, which increases the pressure inside the housing. When the pressure inside the housing increases to a certain level, the gas inside the housing will squeeze the sealing ring until it deforms. The gas can be discharged from the periphery of the deformed sealing ring to the external space of the universal joint. During the gas discharge process, lubricating grease will be discharged along with it, resulting in insufficient lubrication of the universal joint. Summary of the Invention
[0004] To address the problem of grease leakage in universal joints, this invention provides a low-leakage universal joint, comprising:
[0005] Shaft unit;
[0006] A bushing assembly, wherein the bushing assembly is configured as a tube with one end open; the bushing assembly is sleeved on the outer peripheral side of the shaft unit; the inner peripheral wall of the bushing assembly is spaced apart from the outer peripheral wall of the shaft unit to form a sealing space and a rolling space; the sealing space is located on the side of the rolling space near the open end of the bushing assembly.
[0007] Rolling elements, wherein a plurality of the rolling elements are disposed within the rolling space;
[0008] A sealing assembly, the sealing assembly being arranged in an annular shape, is disposed in the sealing space to enclose the rolling space; the sealing space includes an outer balancing cavity and an inner balancing cavity; the outer balancing cavity is a sealed space formed by a portion of the outer peripheral wall of the sealing assembly and a portion of the inner peripheral wall of the bushing assembly; the inner balancing cavity is a sealed space formed by a portion of the inner peripheral wall of the sealing assembly and a portion of the outer peripheral wall of the shaft unit; the outer balancing cavity and the inner balancing cavity are connected through a balancing hole penetrating the radial wall of the sealing assembly.
[0009] In some embodiments, the sealing assembly includes a support unit and a sealing unit; a portion of the outer peripheral wall of the support unit is connected to a portion of the inner peripheral wall of the bushing assembly; the sealing unit includes a first lip, a fourth lip, and a third lip; the first lip and the third lip are respectively connected to the inner peripheral wall of the support unit; one end of the first lip and the third lip away from the support unit abuts against the outer peripheral wall of the bushing unit; one end of the fourth lip is connected to the outer peripheral wall of the support unit, and the other end abuts against the inner peripheral wall of the bushing assembly; the first lip is disposed on the side of the third lip away from the rolling element;
[0010] The rolling space is formed by the third lip, the end of the support unit near the rolling element, a portion of the inner peripheral wall of the bushing assembly, a portion of the closed end of the bushing assembly, and a portion of the outer peripheral wall of the shaft unit; the inner balance cavity is formed by the first lip, the third lip, a portion of the inner peripheral wall of the support unit, and a portion of the outer peripheral wall of the shaft unit; the outer balance cavity is formed by the fourth lip, a portion of the outer peripheral wall of the support unit, and a portion of the inner peripheral wall of the bushing assembly.
[0011] In some embodiments, the area of the fourth lip abutting against the inner peripheral wall of the bushing assembly is smaller than the area of the first lip abutting against the outer peripheral surface of the shaft unit.
[0012] In some embodiments, the sealing unit further includes a second lip; one end of the second lip is connected to the inner circumferential surface of the support unit, and the other end abuts against the shaft unit; the first lip, the second lip, and the third lip are arranged in sequence; A > B; A is the distance between the position of the first lip abutting against the shaft unit and the central axis of the shaft unit along the radial direction of the shaft unit; B is the distance between the position of the second lip abutting against the shaft unit and the central axis of the shaft unit along the radial direction of the shaft unit.
[0013] In some embodiments, the second lip divides the inner balance cavity into a first inner cavity and a second inner cavity; the third lip, the second inner cavity, the second lip, and the first inner cavity are arranged sequentially.
[0014] The sealing unit further includes a connecting groove; the connecting groove extends through both sides of the second lip along the axial direction of the shaft unit; the connecting groove connects the first inner cavity and the second inner cavity.
[0015] In some embodiments, one end of the third lip is disposed on the side of the support unit near the rolling element, and the other end extends to abut against the outer peripheral wall of the shaft unit while tilting towards the direction of the first lip.
[0016] In some embodiments, the support unit includes a first support ring, a second support ring, a boss, and a balance hole; the first support ring and the second support ring are sequentially connected along the direction from the rolling element to the open end of the bushing assembly; the outer peripheral wall of the first support ring is connected to a portion of the inner peripheral wall of the bushing assembly; the outer peripheral wall of the second support ring is spaced apart from the inner peripheral wall of the bushing assembly; one end of the third lip is connected to the inner peripheral wall of the first support ring, and the other end extends to abut against the outer peripheral wall of the bushing unit; one end of the first lip is connected to the inner peripheral wall of the second support ring, and the other end extends to abut against the outer peripheral wall of the bushing unit; one end of the fourth lip is connected to the outer peripheral wall of the second support ring, and the other end is connected to the bushing assembly. The inner peripheral wall of the component abuts against the shaft unit; the first support ring, the bushing assembly, and the shaft unit surround and form the rolling space; the bushing assembly, the fourth lip, and a portion of the second support ring surround and form the outer balance cavity; the first lip, the third lip, a portion of the first support ring, and a portion of the second support ring surround and form the inner balance cavity; the balance hole penetrates the second support ring radially along the shaft unit; one end of the boss is connected to the inner peripheral wall of the second support ring, and the other end extends toward the shaft unit; the boss is disposed on the periphery of the balance hole; the boss and the shaft unit are spaced apart; the inner balance cavity, the space surrounded by the inner peripheral wall of the boss, the balance hole, and the outer balance cavity are sequentially connected.
[0017] In some embodiments, the support unit includes a plurality of the balance holes; adjacent balance holes are spaced apart.
[0018] In some embodiments, the bushing assembly includes a base plate, a first ring, a second ring, and a third ring; the base plate, the first ring, the second ring, and the third ring are sequentially connected along the axial direction of the first ring to form a tubular shape with one end open; the first ring, the second ring, and the third ring are respectively sleeved on the outer periphery of the shaft unit and spaced apart from the shaft unit to form a sealing space and a rolling space; the inner peripheral wall of the first ring abuts against the rolling element; the inner peripheral wall of the second ring abuts against a portion of the outer peripheral wall of the sealing assembly; the inner peripheral wall of the third ring abuts against a portion of the outer peripheral wall of the sealing assembly; the third ring, the second ring, and the sealing assembly surround to form the outer balance cavity.
[0019] In some embodiments, the cross assembly includes a base and a plurality of shaft units; the shaft units are connected to the base; the number of bushing assemblies and the number of sealing assemblies are respectively set to correspond to the number of shaft units; adjacent bushing assemblies are spaced apart.
[0020] To solve the problem of easy grease leakage inside universal joints, the present invention has the following advantages:
[0021] By configuring the bushing assembly as a tube with one open end and fitting it around the outer periphery of the shaft unit, a sealing space and a rolling space are formed between the inner peripheral wall of the bushing assembly and the outer peripheral wall of the shaft unit. The sealing space is located on the side of the rolling space closer to the open end of the bushing assembly. Multiple rolling elements are arranged within the rolling space, allowing the rolling elements to generate rolling friction with both the shaft unit and the bushing assembly. An annular sealing assembly is placed within the sealing space to enclose the rolling space, creating an outer balance cavity surrounded by a portion of the outer peripheral wall of the sealing assembly and a portion of the inner peripheral wall of the bushing assembly, and an inner balance cavity surrounded by a portion of the inner peripheral wall of the sealing assembly and a portion of the outer peripheral wall of the shaft unit. The outer and inner balance chambers are connected by a balance hole that penetrates the radial wall of the sealing assembly. When the relative rotation of the shaft unit and the bushing assembly causes the pressure in the rolling space to increase, the balance hole can bring the pressure in the outer and inner balance chambers closer to equilibrium, thereby reducing the deformation of the sealing assembly. At the same time, during the process of grease and gas moving from the inner balance chamber to the outer balance chamber, the extended movement path increases the probability of grease adhering to the sealing assembly, thereby reducing the amount of grease discharged with the gas into the external space of the low-leakage universal joint. Ultimately, this solves the problem of grease loss due to increased pressure in the universal joint, ensuring good lubrication of the low-leakage universal joint and extending its service life. Attached Figure Description
[0022] Figure 1 A schematic diagram of a low-leakage universal joint according to one embodiment is shown;
[0023] Figure 2 It shows Figure 1 A partial schematic diagram;
[0024] Figure 3 A schematic diagram of a bushing assembly and a sealing assembly according to one embodiment is shown;
[0025] Figure 4 A partial schematic diagram of a low-leakage universal joint according to one embodiment is shown.
[0026] Reference numerals: 10 Cross assembly; 11 Base; 12 Shaft unit; 121 First shaft; 122 First transition shaft; 123 Second shaft; 124 Second transition shaft; 125 Third shaft; 20 Shaft sleeve assembly; 21 Base plate; 22 First ring; 23 Second ring; 24 Third ring; 30 Sealing assembly; 31 Support unit; 311 First support ring; 312 Second support ring; 313 Boss; 314 Balance hole; 32 Sealing unit; 321 First lip; 322 Second lip; 323 Third lip; 324 Fourth lip; 325 Communicating groove; 40 Rolling element. Detailed Implementation
[0027] The present disclosure will now be discussed with reference to several exemplary embodiments. It should be understood that these embodiments are discussed only to enable those skilled in the art to better understand and thus implement the present disclosure, and are not intended to imply any limitation on the scope of the disclosure.
[0028] As used herein, the term "comprising" and its variations are to be interpreted as open-ended terms meaning "including but not limited to". The term "based on" is to be interpreted as "at least partially based on". The terms "one embodiment" and "an embodiment" are to be interpreted as "at least one embodiment". The term "another embodiment" is to be interpreted as "at least one other embodiment". The terms "upper", "lower", "left", "right", "front", "rear", "top", "bottom", "inner", "outer", "vertical", "horizontal", "lateral", "longitudinal", etc., indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings. These terms are primarily for the purpose of better describing this application and its embodiments and are not intended to limit the indicated devices, elements, or components to having a specific orientation or being constructed and operated in a specific orientation. Furthermore, some of the above terms may be used to indicate other meanings besides orientations or positional relationships; for example, the term "upper" may in some cases indicate a dependency or connection relationship. Those skilled in the art can understand the specific meaning of these terms in this application according to the specific circumstances. In addition, the terms "installed", "set up", "equipped with", "connected", and "linked" should be interpreted broadly. For example, it can be a fixed connection, a detachable connection, or an integral structure; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or an internal connection between two devices, elements, or components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances. Furthermore, the terms "first," "second," etc., are mainly used to distinguish different devices, elements, or components (the specific types and structures may be the same or different), and are not used to indicate or imply the relative importance or quantity of the indicated devices, elements, or components. Unless otherwise stated, "a plurality of" means two or more.
[0029] In the structure comprising a shaft unit 12, a bushing assembly 20, a rolling element 40, and a sealing assembly 30, the bushing assembly 20 is fitted around the outer periphery of the shaft unit 12, forming a sealing space and a rolling space with the wall of the shaft unit 12. The rolling element 40 is disposed within the rolling space, and the sealing assembly 30 is disposed within the sealing space to enclose the rolling space. During actual use, the rolling element 40 undergoes rolling friction with both the outer peripheral wall of the shaft unit 12 and the inner peripheral wall of the bushing assembly 20, generating heat during this process. This heat increases the pressure in the internal regions of the rolling space and the sealing space. When the internal pressure reaches a certain level, the internal gas exerts a compressive force on the sealing assembly 30 within the sealing space, causing deformation of the sealing assembly 30. After the sealing component 30 is deformed, the sealing fit between it and the shaft unit 12 and the bushing assembly 20 is disrupted. The internal gas can be discharged from the periphery of the deformed sealing component 30 to the external space. During the gas discharge process, the grease in the rolling space will be discharged together, which will eventually reduce the amount of grease inside the structure and cause insufficient lubrication.
[0030] In this embodiment, as Figure 1 , Figure 2 As shown, the low-leakage universal joint includes a shaft unit 12, a bushing assembly 20, rolling elements 40, and a sealing assembly 30;
[0031] The bushing assembly 20 is configured as a tube with one open end, and the closed end of the bushing assembly 20 can be used to connect to the output end of the power supply. The bushing assembly 20 is sleeved on the outer periphery of the shaft unit 12. The inner peripheral wall of the bushing assembly 20 is spaced apart from the outer peripheral wall of the shaft unit 12 to form a sealing space and a rolling space. The sealing space is located on the side of the rolling space near the open end of the bushing assembly 20, that is, the sealing space and the rolling space can move along... Figure 2 The arrangement is shown from left to right.
[0032] Multiple rolling elements 40 are arranged in the rolling space. The outer peripheral walls of the rolling elements 40 respectively abut against the outer peripheral wall of the shaft unit 12 and the inner peripheral wall of the bushing assembly 20, thereby forming rolling friction and improving the service life of the low leakage universal joint.
[0033] The sealing assembly 30 can be configured as an annular shape; the sealing assembly 30 is disposed on the side of the sealing space away from the rolling space, thus enclosing the rolling space; the sealing space includes an outer balance cavity and an inner balance cavity; the outer balance cavity is formed by the outer peripheral wall of a portion of the sealing assembly 30 and the inner peripheral wall of a portion of the bushing assembly 20; the inner balance cavity is formed by the inner peripheral wall of a portion of the sealing assembly 30 and the outer peripheral wall of a portion of the shaft unit 12; such as Figure 3As shown, the inner balance chamber is located below the outer balance chamber; the outer balance chamber and the inner balance chamber are connected by a balance hole 314 that penetrates the radial wall of the sealing assembly 30; when the shaft unit 12 and the bushing unit rotate relative to each other, the pressure in the rolling space increases, and the balance hole 314 can make the pressure in the outer balance chamber and the inner balance chamber approach or balance, reducing the deformation of the sealing assembly 30, thereby reducing the amount of grease carried by the gas discharged from between the sealing assembly 30 and the bushing assembly 20 and from between the sealing assembly 30 and the shaft unit 12 to the external space of the low-leakage universal joint; at the same time, since the grease and gas can move from the inner balance chamber to the outer balance chamber, the longer the movement path, the greater the probability of the grease adhering to the sealing assembly 30, which can further reduce the amount of grease discharged with the gas to the external space of the low-leakage universal joint, thereby ensuring good lubrication of the low-leakage universal joint and extending its service life.
[0034] Furthermore, such as Figure 2 As shown, the sealing assembly 30 includes a support unit 31 and a sealing unit 32; the outer peripheral wall of part of the support unit 31 is connected to the inner peripheral wall of part of the bushing assembly 20, and the connection can be an interference fit; the sealing unit 32 includes a first lip 321, a fourth lip 324, and a third lip 323; the first lip 321 and the third lip 323 are respectively connected to the inner peripheral wall of the support unit 31; the end of the first lip 321 away from the support unit 31 and the end of the third lip 323 away from the support unit 31 respectively abut against the outer peripheral wall of the shaft unit 12; one end of the fourth lip 324 is connected to the outer peripheral wall of the support unit 31 and the bushing assembly 20 which are spaced apart, and the other end abuts against the inner peripheral wall of the bushing assembly 20; the first lip 321 is located on the side of the third lip 323 away from the rolling element 40;
[0035] The third lip 323, the end of the support unit 31 near the rolling element 40, the inner peripheral wall of part of the bushing assembly 20, the closed end of part of the bushing assembly 20, and the outer peripheral wall of part of the shaft unit 12 surround and form a rolling space. The third lip 323 can reduce the loss of grease from the rolling space. The first lip 321, the third lip 323, the inner peripheral wall of part of the support unit 31, and the outer peripheral wall of part of the shaft unit 12 surround and form an inner balance cavity. The first lip 321 can prevent foreign objects from entering the low-leakage universal joint and reduce the movement of grease from the inner balance cavity to the external space of the low-leakage universal joint. The fourth lip 324... The outer peripheral wall of part of the support unit 31 and the inner peripheral wall of part of the bushing assembly 20 surround and form an outer balance cavity. The fourth lip 324 can reduce the movement of grease from the outer balance cavity to the external space of the low-leakage universal joint. When the pressure in the rolling space increases to a certain level, the gas and grease in the rolling space simultaneously squeeze the third lip 323 to deform, causing at least part of the third lip 323 to be spaced from the shaft unit 12, connecting the inner balance cavity and the rolling space. Subsequently, the gas and grease in the rolling space can enter the inner balance cavity, and some of the gas and grease can enter the outer balance cavity from the inner balance cavity through the balance hole 314. The connection between the outer peripheral wall of part of the support unit 31 and the inner peripheral wall of part of the bushing assembly 20 can limit the range of movement of the support unit 31 toward the bushing assembly 20, that is, limit the movement of the support unit 31 as it moves toward the bushing assembly 20. Figure 2 As shown, the upward curvature of the left end means that when gas and grease enter the outer and inner balance chambers simultaneously and the pressures in both chambers are relatively high, the fourth lip 324 will deform more easily than the first lip 321. This allows the gas and grease to move more easily through the inner peripheral wall of the fourth lip 324 and the bushing assembly 20 to the external space of the low-leakage universal joint. The fourth lip 324 will release pressure before the first lip 321, thereby extending the path of the gas and grease from the rolling space to the external space of the low-leakage universal joint, and thus reducing the amount of grease carried with the gas as it is discharged to the external space of the low-leakage universal joint.
[0036] Furthermore, such as Figure 2 As shown, the area of the fourth lip 324 abutting against the inner peripheral wall of the bushing assembly 20 is smaller than the area of the first lip 321 abutting against the outer peripheral surface of the shaft unit 12. This results in a larger force required to deform the first lip 321 to a distance from the shaft unit 12, and a smaller force required to deform the fourth lip 324 to a distance from the bushing assembly 20. This allows gas and grease in the inner balance chamber to more easily enter the outer balance chamber through the balance hole 314, further facilitating the flow of gas and grease between the fourth lip 324 and the inner peripheral wall of the bushing assembly 20 to the external space of the low-leakage universal joint. In this way, the path of gas and grease flowing from the rolling space to the external space of the low-leakage universal joint is extended. A longer path makes it easier for air bubbles in the grease to separate from each other, ultimately reducing the amount of grease discharged with the gas into the external space of the low-leakage universal joint.
[0037] Furthermore, such as Figure 2 , Figure 4 As shown, the sealing unit 32 also includes a second lip 322; one end of the second lip 322 is connected to the inner circumferential surface of the support unit 31, and the other end abuts against the shaft unit 12; the first lip 321, the second lip 322, and the third lip 323 are arranged in sequence; A > B; A is the distance between the position of the first lip 321 abutting against the shaft unit 12 and the central axis of the shaft unit 12 along the radial direction of the shaft unit 12; B is the distance between the position of the second lip 322 abutting against the shaft unit 12 and the central axis of the shaft unit 12 along the radial direction of the shaft unit 12; when the grease moves from the rolling space through the third lip 323 to between the second lip 322 and the third lip 323, the second lip 322 can impede the movement of the grease, thereby ensuring good lubrication of the low-leakage universal joint during use; A > B can provide a force to the second lip 322 in the direction of the rolling element 40, that is, as Figure 2 The force acting from left to right is shown to prevent the sealing unit 32 from moving from the open end of the bushing assembly 20 to a distance from the shaft unit 12 and / or the bushing assembly 20 during use.
[0038] Furthermore, such as Figure 2 As shown, the second lip 322 divides the inner balance cavity into a first inner cavity and a second inner cavity; the third lip 323, the second inner cavity, the second lip 322, and the first inner cavity are arranged in sequence;
[0039] like Figure 3 As shown, the sealing unit 32 also includes a connecting groove 325; the connecting groove 325 extends along both sides of the second lip 322 through the axial portion of the shaft unit 12; the connecting groove 325 connects the first inner cavity and the second inner cavity. When the grease enters the first inner cavity, over time, the grease can return from the connecting groove 325 to the second inner cavity, which is farther from the opening end of the bushing assembly 20, thus extending the path of the grease from inside the low-leakage universal joint to outside the low-leakage universal joint and reducing the risk of grease leakage.
[0040] Furthermore, the sealing unit 32 may include a plurality of communicating grooves 325, which are spaced apart circumferentially along the support unit 31.
[0041] Furthermore, such as Figure 2As shown, with the use of low-leakage universal joints, if the temperature rises in the rolling space, causing excessive pressure, the sealing assembly 30 will be driven by air pressure to move towards the open end of the bushing assembly 20, making the connection between the sealing assembly 30 and the bushing assembly 20 unstable and / or the connection between the sealing assembly 30 and the shaft unit 12 unstable. One end of the third lip 323 is located on the side of the support unit 31 near the rolling element 40, and the other end extends to abut against the outer peripheral wall of the shaft unit 12 while tilting towards the first lip 321. When the pressure in the rolling space is high, the gas and grease in the rolling space can squeeze the third lip 323 to deform so that the third lip 323 is at least partially separated from the shaft unit 12, thereby allowing the rolling space to connect with the sealing space, reducing the pressure in the rolling space, and ensuring the stability of the connection between the sealing assembly 30 and the bushing assembly 20 and / or the shaft unit 12.
[0042] Furthermore, such as Figure 2 As shown, the support unit 31 includes a first support ring 311, a second support ring 312, a boss 313, and a balance hole 314; the first support ring 311 and the second support ring 312 are along the direction from the rolling element 40 to the open end of the bushing assembly 20 (i.e., as shown in the figure). Figure 2 (As shown from right to left) are connected sequentially; the outer peripheral wall of the first support ring 311 is connected to the inner peripheral wall of part of the bushing assembly 20, and the connection method can be an interference fit; the outer peripheral wall of the second support ring 312 is spaced apart from the inner peripheral wall of the bushing assembly 20, and is used to connect the third lip 323; one end of the third lip 323 is connected to the inner peripheral wall of the first support ring 311, and the other end extends to abut against the outer peripheral wall of the shaft unit 12; one end of the first lip 321 is connected to the inner peripheral wall of the second support ring 312, and the other end extends to abut against the outer peripheral wall of the shaft unit 12; one end of the fourth lip 324 is connected to the outer peripheral wall of the second support ring 312, and the other end abuts against the inner peripheral wall of the bushing assembly 20; the first support ring 311, the bushing assembly 20, and the shaft unit 12 surround to form a rolling space; the bushing assembly 20, the fourth lip 324, and part of the second support ring 312 surround... An outer balance cavity is formed; an inner balance cavity is formed by the first lip 321, the third lip 323, a portion of the first support ring 311, and a portion of the second support ring 312; a balance hole 314 penetrates the second support ring 312 radially along the shaft unit 12; one end of the boss 313 is connected to the inner peripheral wall of the second support ring 312, and the other end extends toward the shaft unit 12; the boss 313 is disposed on the periphery of the balance hole 314; the boss 313 is spaced apart from the shaft unit 12; the inner balance cavity, the space surrounded by the inner peripheral wall of the boss 313, the balance hole 314, and the outer balance cavity are sequentially connected; due to the presence of the boss 313, the grease in the inner balance cavity at the bottom of the low-leakage universal joint can be temporarily stored on the periphery of the boss 313, instead of directly entering the outer balance cavity through the space surrounded by the inner peripheral wall of the boss 313 and the balance hole 314, which can further reduce grease leakage.
[0043] Furthermore, such as Figure 1 , Figure 3 As shown, the support unit 31 includes a plurality of balance holes 314; adjacent balance holes 314 are spaced apart; this can reduce the pressure difference between the inner and outer circumferential surfaces of the entire sealing assembly 30, thereby reducing the deformation of the entire sealing assembly 30 and reducing grease leakage.
[0044] Furthermore, such as Figure 4 As shown, the bushing assembly 20 includes a base plate 21, a first ring 22, a second ring 23, and a third ring 24. The base plate 21, the first ring 22, the second ring 23, and the third ring 24 are sequentially connected along the axial direction of the first ring 22 to form a tubular shape with one end open. The base plate 21 can be used to connect the input or output end of the power. The first ring 22, the second ring 23, and the third ring 24 are respectively sleeved on the outer periphery of the shaft unit 12 and spaced apart from the shaft unit 12 to form a sealing space and a rolling space. The inner peripheral wall of the first ring 22 abuts against the rolling element 40. During the use of the low-leakage universal joint, the first ring 22 and the rolling element 40 form rolling friction to reduce friction. The inner peripheral wall of the second ring 23 is connected to part of the outer peripheral wall of the sealing component 30, and the connection method can be an interference fit. The inner peripheral wall of the third ring 24 abuts against part of the outer peripheral wall of the sealing component 30. The third ring 24, the second ring 23, and the sealing component 30 surround and form an outer balance cavity.
[0045] Furthermore, such as Figure 1 As shown, the cross assembly 10 includes a base 11 and multiple shaft units 12; the shaft units 12 are connected to the base 11; the number of bushing assemblies 20 and the number of sealing assemblies 30 are respectively set to correspond to the number of shaft units 12. Typically, there are 4 shaft units 12, which are arranged at 90° to each other. Two bushing assemblies 20 can be connected to the power input end, and the other two bushing assemblies 20 can be connected to the power output end, so that power transmission can be completed even when there is a certain angle between the power input end and the power output end; adjacent bushing assemblies 20 are spaced apart to avoid mutual interference.
[0046] Further, the shaft unit 12 includes a first shaft 121, a first transition shaft 122, a second shaft 123, a second transition shaft 124, and a third shaft 125; the first shaft 121, the first transition shaft 122, the second shaft 123, the second transition shaft 124, and the third shaft 125 are coaxially connected sequentially along the direction from the first lip 321 to the third lip 323; the outer peripheral wall of the third shaft 125 abuts against the outer peripheral wall of the rolling element 40; R5 > R1 = R2 > R3 = R4; where R1 is the radius of the first shaft 121; R2 is the radius of the first transition shaft 122 near the first shaft 121; R3 is the radius of the first transition shaft 122 away from the first shaft 121; R4 is the radius of the second shaft 123; R5 is the distance between the side of the rolling element 40 away from the shaft unit 12 and the central axis of the third shaft 125 radially along the third shaft 125, which can provide sufficient space between the shaft unit 12 and the bushing assembly 20 for installing the sealing assembly 30; the first transition shaft 121... The radius of 2 gradually changes, allowing for a smooth transition between the first transition shaft 122 and the first shaft 121, avoiding stress concentration; the end of the first lip 321 away from the support unit 31 abuts against the outer peripheral wall of the first shaft 121; the end of the third lip 323 away from the support unit 31 abuts against the outer peripheral wall of the second shaft 123; the sealing unit 32 also includes a second lip 322; one end of the second lip 322 is connected to the inner peripheral surface of the support unit 31, and the other end abuts against the second transition shaft 124; the first lip 321, the second lip 322, and the third lip 323 are arranged sequentially; the first lip 321, the first shaft 121, the first transition shaft 122, part of the second shaft 123, the third lip 323, and the inner peripheral surface of the support unit 31 surround to form an inner balance cavity; the third lip 323, the support unit 31, part of the inner peripheral wall of the bushing assembly 20, part of the unopened end of the bushing assembly 20, the third shaft 125, the second transition shaft 124, and part of the second shaft 123 surround to form a rolling space.
[0047] Those skilled in the art will understand that the above embodiments are specific examples of implementing this disclosure, and in practical applications, various changes can be made in form and detail without departing from the scope of this disclosure.
Claims
1. A low-leakage universal joint, characterized in that, The low-leakage universal joint includes: Shaft unit; A bushing assembly, wherein the bushing assembly is configured as a tube with one end open; the bushing assembly is sleeved on the outer peripheral side of the shaft unit; the inner peripheral wall of the bushing assembly is spaced apart from the outer peripheral wall of the shaft unit to form a sealing space and a rolling space; the sealing space is located on the side of the rolling space near the open end of the bushing assembly. Rolling elements, wherein a plurality of the rolling elements are disposed within the rolling space; A sealing assembly, the sealing assembly being arranged in an annular shape, is disposed in the sealing space to enclose the rolling space; the sealing space includes an outer balancing cavity and an inner balancing cavity; the outer balancing cavity is a sealed space formed by a portion of the outer peripheral wall of the sealing assembly and a portion of the inner peripheral wall of the bushing assembly; the inner balancing cavity is a sealed space formed by a portion of the inner peripheral wall of the sealing assembly and a portion of the outer peripheral wall of the shaft unit; the outer balancing cavity and the inner balancing cavity are connected through a balancing hole penetrating the radial wall of the sealing assembly; The sealing assembly includes a support unit and a sealing unit; a portion of the outer peripheral wall of the support unit is connected to a portion of the inner peripheral wall of the bushing assembly; the sealing unit includes a first lip, a fourth lip, and a third lip; the first lip and the third lip are respectively connected to the inner peripheral wall of the support unit; the ends of the first lip and the third lip away from the support unit respectively abut against the outer peripheral wall of the bushing unit; one end of the fourth lip is connected to the outer peripheral wall of the support unit, and the other end abuts against the inner peripheral wall of the bushing assembly; the first lip is disposed on the side of the third lip away from the rolling element; The rolling space is formed by the third lip, the end of the support unit near the rolling element, a portion of the inner peripheral wall of the bushing assembly, a portion of the closed end of the bushing assembly, and a portion of the outer peripheral wall of the shaft unit; the inner balance cavity is formed by the first lip, the third lip, a portion of the inner peripheral wall of the support unit, and a portion of the outer peripheral wall of the shaft unit; the outer balance cavity is formed by the fourth lip, a portion of the outer peripheral wall of the support unit, and a portion of the inner peripheral wall of the bushing assembly. The sealing unit further includes a second lip; one end of the second lip is connected to the inner circumferential surface of the support unit, and the other end abuts against the shaft unit; the first lip, the second lip, and the third lip are arranged in sequence; A > B; A is the distance between the position of the first lip abutting against the shaft unit and the central axis of the shaft unit along the radial direction of the shaft unit; B is the distance between the position of the second lip abutting against the shaft unit and the central axis of the shaft unit along the radial direction of the shaft unit.
2. The low-leakage universal joint according to claim 1, characterized in that, The area where the fourth lip abuts against the inner peripheral wall of the bushing assembly is smaller than the area where the first lip abuts against the outer peripheral surface of the shaft unit.
3. A low-leakage universal joint according to claim 1, characterized in that, The second lip divides the inner balance cavity into a first inner cavity and a second inner cavity; the third lip, the second inner cavity, the second lip, and the first inner cavity are arranged sequentially. The sealing unit further includes a connecting groove; the connecting groove extends through both sides of the second lip along the axial direction of the shaft unit; the connecting groove connects the first inner cavity and the second inner cavity.
4. A low-leakage universal joint according to claim 1, characterized in that, One end of the third lip is disposed on the side of the support unit near the rolling element, and the other end extends to abut against the outer peripheral wall of the shaft unit while tilting towards the first lip.
5. A low-leakage universal joint according to claim 1, characterized in that, The support unit includes a first support ring, a second support ring, a boss, and a balance hole; the first support ring and the second support ring are connected sequentially along the direction from the rolling element to the open end of the bushing assembly; the outer peripheral wall of the first support ring is connected to a portion of the inner peripheral wall of the bushing assembly; the outer peripheral wall of the second support ring is spaced apart from the inner peripheral wall of the bushing assembly; one end of the third lip is connected to the inner peripheral wall of the first support ring, and the other end extends to abut against the outer peripheral wall of the shaft unit; One end of the first lip is connected to the inner peripheral wall of the second support ring, and the other end extends to abut against the outer peripheral wall of the shaft unit; One end of the fourth lip is connected to the outer peripheral wall of the second support ring, and the other end abuts against the inner peripheral wall of the bushing assembly; the first support ring, the bushing assembly, and the shaft unit surround to form the rolling space; the bushing assembly, the fourth lip, and part of the second support ring surround to form the outer balance cavity; the first lip, the third lip, part of the first support ring, and part of the second support ring surround to form the inner balance cavity; the balance hole penetrates the second support ring radially along the shaft unit; one end of the boss is connected to the inner peripheral wall of the second support ring, and the other end extends toward the shaft unit; the boss is disposed on the periphery of the balance hole; the boss and the shaft unit are spaced apart; the inner balance cavity, the space surrounded by the inner peripheral wall of the boss, the balance hole, and the outer balance cavity are sequentially connected.
6. A low-leakage universal joint according to claim 5, characterized in that, The support unit includes a plurality of balance holes; adjacent balance holes are spaced apart.
7. A low-leakage universal joint according to claim 1, characterized in that, The bushing assembly includes a base plate, a first ring, a second ring, and a third ring; the base plate, the first ring, the second ring, and the third ring are sequentially connected along the axial direction of the first ring to form a tube with one end open; the first ring, the second ring, and the third ring are respectively sleeved on the outer periphery of the shaft unit and spaced apart from the shaft unit to form a sealing space and a rolling space; the inner peripheral wall of the first ring abuts against the rolling element; the inner peripheral wall of the second ring abuts against a portion of the outer peripheral wall of the sealing assembly; the inner peripheral wall of the third ring abuts against a portion of the outer peripheral wall of the sealing assembly; the third ring, the second ring, and the sealing assembly surround to form the outer balance cavity.
8. A low-leakage universal joint according to claim 1, characterized in that, The cross assembly includes a base and a plurality of shaft units; the shaft units are connected to the base; the number of bushing assemblies and the number of sealing assemblies are respectively set to correspond to the number of shaft units; adjacent bushing assemblies are spaced apart.
Citation Information
Patent Citations
Long-life universal joint capable of realizing exhausting and free of oil leakage
CN110043570A
Constant velocity universal joint
JP2007205549A